ci(static-checks): derive the lint job's expect-vip from x64-4 to match its runs-on

Moving `lint` to `RUNNER_LINUX_X64_4` left its Configure Registry step's
`expect-vip` still derived from `RUNNER_LINUX_X64_8`. Flagged by both
greptile-apps and coderabbitai on line 74.

`expect-vip` tells the pinned configure-registry action (aa4ee199) that the
runner is in-network: it probes the Verdaccio VIP twice instead of once and
emits "Verdaccio VIP unreachable from an in-network runner" on failure. Either
way the job falls back to public npm and never fails - it is a diagnostic.

Every other job in the repo derives `expect-vip` from the same variable as its
`runs-on` (all nine x64-8 jobs read x64-8; the matrix release jobs use
"self-hosted or ever-k8s"). `lint` was the only mismatch, introduced by the
previous commit. This restores the invariant.

Took greptile's fix (derive from x64-4). Did NOT take coderabbit's literal
`false`: x64-4 is an in-network ARC runner, so `false` would make `lint` the one
self-hosted job with no retry and no warning, turning a registry outage on that
lane into a silent single-probe fallback.

No behaviour change today, since both variables are set org-wide; this closes
the case where x64-4 is configured and x64-8 is not.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/static-checks.yml

@@ -112,7 +112,7 @@ jobs:
           verdaccio-registry: ${{ vars.VERDACCIO_REGISTRY }}
           verdaccio-token: ${{ secrets.VERDACCIO_TOKEN }}
           force-public: ${{ vars.VERDACCIO_FORCE_PUBLIC }}
-          expect-vip: ${{ vars.RUNNER_LINUX_X64_8 != '' }}
+          expect-vip: ${{ vars.RUNNER_LINUX_X64_4 != '' }}
 
       - name: Restore node_modules
         shell: bash